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我正在尝试制作墙纸应用程序。我在用位图设置壁纸时遇到了大麻烦。我试图找出一个星期的答案。

我想将位图设置为壁纸

  1. 避免作物
  2. scaleType:fit_center(对齐中心垂直，纵横比)

我怎样才能做到？

PS我发现也许我可以使用Bitmap.createBitmap，但我的尝试一次又一次地失败了。我不知道我应该只使用 WallPaperManager 还是同时使用 Bitmap.createBitmp。

static Bitmap createBitmap(Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter)

    public void setScreenBitmap(final Bitmap bitmapInputed)
{

    final WallpaperManager wpm = WallpaperManager.getInstance(myContext);

    final Display display = ((Activity) this.myContext).getWindowManager().getDefaultDisplay();

    Point size = new Point();
    display.getSize(size);
    int width = size.x;
    int height = size.y; 


    try 
    {
        wpm.setBitmap(Bitmap.createScaledBitmap(bitmapInputed, width, height, true));
    }
    catch (IOException e) 
    {
        Log.e(TAG+".setScreenBitmap", e.toString());
        e.printStackTrace();
    }
    wpm.setWallpaperOffsetSteps(1.0f, 1.0f);

    wpm.suggestDesiredDimensions(width, height);

}






 09-06 20:38:15.563: W/System.err(4892): java.lang.IllegalArgumentException: x must be >= 0
09-06 20:38:15.563: W/System.err(4892):     at android.graphics.Bitmap.checkXYSign(Bitmap.java:285)
09-06 20:38:15.563: W/System.err(4892):     at android.graphics.Bitmap.createBitmap(Bitmap.java:580)
09-06 20:38:15.568: W/System.err(4892):     at android.graphics.Bitmap.createBitmap(Bitmap.java:551)
09-06 20:38:15.568: W/System.err(4892):     at com.myarena.util.MyWallpaperUtil.getBitmapFromCenterAndScreenSize(MyWallpaperUtil.java:459)
09-06 20:38:15.568: W/System.err(4892):     at com.myarena.util.MyWallpaperUtil.setScreenBitmap(MyWallpaperUtil.java:485)
09-06 20:38:15.568: W/System.err(4892):     at com.myarena.util.MyWallpaperUtil.changeWallpaper(MyWallpaperUtil.java:231)
09-06 20:38:15.568: W/System.err(4892):     at com.myarena.controller.ControllerActivity$PlaceholderFragment$2.onClick(ControllerActivity.java:213)
09-06 20:38:15.568: W/System.err(4892):     at android.view.View.performClick(View.java:4489)
09-06 20:38:15.568: W/System.err(4892):     at android.view.View$PerformClick.run(View.java:18803)
09-06 20:38:15.568: W/System.err(4892):     at android.os.Handler.handleCallback(Handler.java:730)
09-06 20:38:15.568: W/System.err(4892):     at android.os.Handler.dispatchMessage(Handler.java:92)
09-06 20:38:15.568: W/System.err(4892):     at android.os.Looper.loop(Looper.java:137)
09-06 20:38:15.568: W/System.err(4892):     at android.app.ActivityThread.main(ActivityThread.java:5493)
09-06 20:38:15.568: W/System.err(4892):     at java.lang.reflect.Method.invokeNative(Native Method)
09-06 20:38:15.568: W/System.err(4892):     at java.lang.reflect.Method.invoke(Method.java:525)
09-06 20:38:15.568: W/System.err(4892):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209)
09-06 20:38:15.568: W/System.err(4892):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025)
09-06 20:38:15.568: W/System.err(4892):     at dalvik.system.NativeStart.main(Native Method)
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1 回答 1

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如果您想从中心和相同的屏幕分辨率裁剪位图，请使用以下方法。此处返回位图与您的屏幕分辨率和裁剪相同。

对于前。您的位图大小 480x820

您的设备尺寸为 480x800，其返回 480x800（缩放后去除顶部 10 像素和底部 10 像素）。

您的设备尺寸为 800x1280，其返回 800x1280（缩放后移除顶部 43 像素和底部 43 像素）。

private Bitmap cropBitmapFromCenterAndScreenSize(Bitmap bitmap) {
    float screenWidth, screenHeight;
    float bitmap_width = bitmap.getWidth(), bitmap_height = bitmap
            .getHeight();
    Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE))
            .getDefaultDisplay();
    screenWidth = display.getWidth();
    screenHeight = display.getHeight();

    Log.i("TAG", "bitmap_width " + bitmap_width);
    Log.i("TAG", "bitmap_height " + bitmap_height);

    float bitmap_ratio = (float) (bitmap_width / bitmap_height);
    float screen_ratio = (float) (screenWidth / screenHeight);
    int bitmapNewWidth, bitmapNewHeight;

    Log.i("TAG", "bitmap_ratio " + bitmap_ratio);
    Log.i("TAG", "screen_ratio " + screen_ratio);

    if (screen_ratio > bitmap_ratio) {
        bitmapNewWidth = (int) screenWidth;
        bitmapNewHeight = (int) (bitmapNewWidth / bitmap_ratio);
    } else {
        bitmapNewHeight = (int) screenHeight;
        bitmapNewWidth = (int) (bitmapNewHeight * bitmap_ratio);
    }

    bitmap = Bitmap.createScaledBitmap(bitmap, bitmapNewWidth,
            bitmapNewHeight, true);

    Log.i("TAG", "screenWidth " + screenWidth);
    Log.i("TAG", "screenHeight " + screenHeight);
    Log.i("TAG", "bitmapNewWidth " + bitmapNewWidth);
    Log.i("TAG", "bitmapNewHeight " + bitmapNewHeight);

    int bitmapGapX, bitmapGapY;
    bitmapGapX = (int) ((bitmapNewWidth - screenWidth) / 2.0f);
    bitmapGapY = (int) ((bitmapNewHeight - screenHeight) / 2.0f);

    Log.i("TAG", "bitmapGapX " + bitmapGapX);
    Log.i("TAG", "bitmapGapY " + bitmapGapY);

    bitmap = Bitmap.createBitmap(bitmap, bitmapGapX, bitmapGapY,
            screenWidth,screenHeight);
    return bitmap;
}
于 2014-09-06T10:35:47.953 回答